Light-irradiation thermal treatment apparatus

Abstract

A ring support is attached to an inner wall surface of a chamber that houses a semiconductor wafer to support a susceptor. When the semiconductor wafer is placed on the susceptor, an inner space of the chamber is separated into an upper space and a lower space. Particles are likely to accumulate on a lower chamber window as a floor part of the chamber. However, since the upper space and the lower space are separated, the semiconductor wafer can be prevented from being contaminated by the particles flowing into the upper space and adhering to a surface of the semiconductor wafer even when the particles on the lower chamber window are blown up by irradiation with flash light.

What is claimed is: 
     
       1. A thermal treatment method for housing a substrate in a chamber and performing thermal treatment on the substrate, the thermal treatment method comprising the steps of:
 (a) partitioning the chamber into an upper space and a lower space, with a support member attached to an inner wall surface of the chamber and extending along an inner peripheral direction of the chamber, and a plate quartz susceptor supported by the support member, wherein the upper space is defined to be a space surrounded by the upper chamber window of the chamber, the susceptor, and the support member, and the lower space is defined to be a space surrounded by the lower chamber window of the chamber, the susceptor, and the inner wall surface of the chamber; 
 (b) arranging continuously turned-on lamps below the chamber; 
 (c) arranging flash lamps above the chamber; 
 (d) supporting the substrate on the susceptor for housing the substrate in the upper space; 
 (e) supplying nitrogen gas from a first gas source to the lower space via a first tube; 
 (f) supplying reactive gas from a second gas source to the upper space via a second tube; 
 (g) preheating the substrate by irradiating, through the lower space, a back surface of the substrate with light from the continuously turned-on lamps arranged below the chamber; 
 (h) measuring a temperature of the back surface of the substrate by a radiation thermometer disposed below the susceptor; and 
 (i) turning on the flash lamps to irradiate a front surface of the substrate with flash light when the radiation thermometer detects that the temperature of the substrate has reached a predetermined preheating temperature. 
 
     
     
       2. The thermal treatment method according to  claim 1 ,
 wherein the radiation thermometer is calibrated for use in a nitrogen atmosphere. 
 
     
     
       3. The thermal treatment method according to  claim 1 , further comprising
 (j) discharging the gas from the upper space and the lower space in the chamber, 
 wherein in said step (j), the gas is discharged from the upper space and the lower space using a shared discharge mechanism.